Metal-working machine for making punched nut blanks



Feli. 19 1929. 1,702,320

G. 5. SMITH IE'I'AL WORKING IACHINE FOR IAKING PUNCHBD NUT BLANKS Filed not. 8. 1925 s Sheets-Sheet 1 FAQ. 19, 1929. 1,102,320

s. SMITH X ETAL WORKING MACHINE FOR IAKING PUNCHED NUT BLANKS 7 Filed Oct. 8, 1925 3 Sheets-Sheet 2 Fll3.Z. 94' W MM 9M643 771W Feb. 19, 1929. 1,102,320

G. 5. SMITH IETAL WORKING MACHINE FOR MAKING PUNCHBD NUT BLANKS Filed 001:. 8,, 1925 s Sheets-Sheet 3 -50 nism and a nut blank at the beginnin Patented Feb. 19, 1929.

UNITED. s 'rA 'rss PATENT OFFICE.

GEORGE B. SMITH, OI PITTSBURGH, PENNSYLVANIA, ABSIGNOR, BY MESNE ASSIGN- KEN'I'B, TO PITTSBURGH SGREW AND BOLT OOBPORATION, A CORPORATION OI PENNSYLVANIA.

I'LL-WORKING MACHINE FOR MAKING PUNCHED NUT BLANKS.

Application filed mma, 1525. Serial in. 61,196.

This invention relates-to metal working machines and more articularly to machines for making punched nut blanks from a bar or rod of stock.

The type of machine now generally used for manufacturing square nuts inclu es a die over which the end of the stock is fed and a cooperatin lunger or punch which cuts off the end 0 t e stock and forces it through the die to form a rough blank of square cross section. A transfer finger then engages the blank and moves it into position over a finishing die where it is engaged and held by a posltionin means such as a pair of spring pressedblan engagingjaws.

Heretofore' it has been impossible to adapt this type of machine to the manufacture of hexagon nuts merely by changing the dies for the reason that the difference in sha e of the cut blank prevented the transfer nger from properly positioning the rough blank in the jaws over the finishing die.

An object of this invent-ion is to provide a nut making machine of the type set forth which can be adapted' for either square or hexagonal nuts by merely changing the dies. A further object is to provide a machine of the type set forth having a transfer mechanism constructed and arranged to properly position a nut blank with relation to the holding jaws so that the blank will be accurately positioned over the finishing die regardless of whether it is square or hexagonal in shape. 7

These and other objects which will be obvious to those skilled in this particular art are accomplished by means of this invention, the preferred embodiment of WhlCh lS illustrated in the accompanying drawmgs, in which Figure 1 is a view in elevation of a nut making machine constructed in accordance with this invention and embodying the preferred form of transfer mechanism. Fig. 2 is a horizontal transverse sectional view on the line 22 of Fig. 1. Fig. 3 is a vertical section on the line 33 of Fig. 2. Fig. 4 is a similar view on the line 4-4 of Fig. 2 and Figs. 5 and 6 are diagrammatic views showing the relation between the transfer mechaci an end of the transfer operation respective y.

The illustrated embodiment of this invention is shown as applied to a well-known form of nut making machine having the usual reciprocating plunger head 5' operated from a crank shaft 6 driven through spur gears 7 and 8 by a ulley 9 from any suitable source of power {not shown).

The ceding and operating mechanism of the machine can be of any standard construction and a detailed description thereof is not necessary for the purposes of this applica tion.

The feed mechanism (not shown) intermittently feeds the stock 10 into the machine beneath the reciprocating plunger head. The latter is provided with a punch 11 which cooperates with a punch die 12 secured in a die block 13 for punching out the stock which is fed past the punch beneath a stripper plate 14. The unched out slug drops out of the machine t rough a channel 15.

A blank forming cutting punch 16 is also secured in the die head 5 and cooperates with a blank forming die 17 secured in the die blank at the blank forming station to form a rough nut blank 18 which is cut from the end of the punched stock. At this forming station and beneath the blank forming die 17 is an annular chamfering die 19 adapted to chamfer the lower face of the nut blank when it is forced thereinto b the descent of the punch 16 through the orming die 17. An e ector 20 is mounte for reciprocation within a bore 21 in the machine frame in axial alignment with the chamfering die and is adapted to be actuated by a helical 5 ring 22 so as to raise the rough blank away rom the chamfering die in the usual manner. A finishing station is located at one side of the latter die and consists of a finishing die 23 for finishing the surface of the rough blank 18 when the latter is forced therethrough by the punch 24 secured to the plunger head 5. Blank engaging jaws 25 are pivotally mounted in rackets 26 secured to the machine frame at the finishing station and are spring pressed toward each other by a spring 27 the inward movement of the jaws being limited by pins 28. The blank engaging ends 29 of the jaws are adapted to receive andv hold the rough blank 18 in the proper position over the finishing die 23 so that the descent of the punch 24 will force the blank through the die and provide it with a more or less finished surface.

The transfer mechanism for moving the rough blank 18 from the blank forming stacenter line of the stock bar.

1 with a pin 37 which cooperates with a cam 37* provided upon the end of the crank shaft 6 for oscillating the lever and reciprocating the transfer finger.

Upon each descent of the plunger head 5 the T punch 11 punches a fresh opening in the stock 7 10 and the cutting punch 16 cuts off a fresh blank from the end of the stock and forces it through the forming die 17 into the chamfering die 19 where the lower face is chamfered in the usual manner. Upon recession of the plunger head and cutting punch 16 the ejector 20 lifts the blank 18 out of the chamfering die to the position shown in Figs. 3 and 4. At this moment the cam 37" actuates the lever 35 so as to move the transfer finger 32 inwardly against the blank 18 and the latter is thereby moved into position over the finishing die 23 between the blank engaging sections 29 of the spring pressed jaws 25.

As best illustrated in Fig. 2, a hexagon blank is cut from the stock bar in such a way that opposite sides of the bar form opposite flat sides of the hexagon so that the apex between two'adjacent angular faces falls in the in this way-produces a minimum amount of waste.

It will be obvious from an inspection of Fig. 2 that while a square blank can be moved from the blank forming station directly into the positioning jaws 25 so as to have the opposite flat sides thereof engaged by the opposed jaws, such a movement is impossible with a hexagon blank for the reason that if the blank in Fig. 2 is moved squarely into the holding jaws the latter will engage opposite corners of the blank instead of opposite flat surfaces. The result would be a turning of the blank in the jaws under the pressure of the spring 27 upon withdrawal of the transfer finger 32 and a resultant misalignment of the blank with relation to the finishing die 23.

In order to eliminate this disadvantage and to present a hexagon blank to the holding jaws in such a way that the latter will ongage opposite flat faces of the blank, the transfer finger 32 is slightly offset from the center of the nut blank and the blank engaging end thereof is out so as to form a notch or concave recess 40, the sides of which generally correspond in angularity to two adja: cent sides of the nut blank. As a consequence the engagement of the transfer finger with the nut blank 18 causes a turning movement of the latter as shown in Figs. 5 and 6, due

Cutting a blank to the offsetting of the transfer finger from the axis of the blank and to the angular recess formed in the end thereof so that the The lever 35 has a bifurcated end 41 which straddles the transfer finger supporting bar 33 between collars 42 and 43. The bar and finger are moved inwardly by the lever operating against the collar 43 and the latter is secured to the finger supporting bar by a breakable pin 44 so that if any undue resistance is encountered on the inward movement of the transfer finger the pin 44 will breakbefore any damage'can be done to the machine or parts. A helical spring 45 is interposed between the collar and the frame of the machine for maintaining the collar in constant engagement with the operating lever 35.

What I claim as new and desire to secure by Letters Patent is:

1. A nut forming machine having in combination a blank formin die, a finishing die, reciprocatory means blank from said forming die to said finis ing die, the blank engagingface of said means being constructed and arranged so as to rotate said blank by engagement therewith. 2. A nut forming machine having in combination a blank forming die, a finishing die and means including a reciprocatin for transferring a blank from said orming die to said finishing die, the blank engaging end of said finger being formed so as to partially rotate said blank upon engagement thereby.

3. A machine for forming hexagon nuts having in combination a hexagon blank forming station, a finishing station, spring pressed or transferrin .a

finger jaws for engaging the blank at said finishing station and means for engaging the blank at said forming station and for movin it into engagement with said jaws, the blan engaging portion of said means being formed so as to cause said blank to turn by engagement therewith.

4. A machine for forming hexagon nuts having in combination a hexagon blank forming station, a finishing station, sprin pressed jaws for engaging a blank at sai nishing station, a reciprocable transfer finger for moving a blank from said formin station into engagement with said jaws, sai finger-having an angular recess in the blank engaging end thereof for causing said blank to turn about its axis during transfer movement so that opposed flat faces of said blank are engaged by said jaws.

5. A nut forming machine having in combination a blank formin die, a finishing die and at notched transfer er having means for moving a blank from said forming to said finishing die, said means being offset from the center of the blank so as to effect the rotation thereof.

6. A nut forming machine having in combination a blank forming die, a finishing die and a reciprocatory transfer finger for moving a blank from said forming to said finishin die and movable alon aline offset with "relation to the center of said blank so as to side of a blank so as to cause partial turning thereof by engagement therewith.

n testimony whereof, I have hereunto subscribed my name this 5th day of October,

GEORGE S. SMITH. 

